Bermuda-based Michael Murphy, regarded as a long-time confidant of Mr Greenberg’s, was fired after 32 years’ service and the company’s Bermuda operations sealed. An AIG spokesman said Mr Murphy was fired for filing to co-operate with the government investigators.

AIG’s CFO, Howard Smith, and Vice President Reinsurance Christian Milton were fired two weeks ago for the same reason – in that they invoked their constitutional right to remain silent.

After Mr Murphy was fired, the Bermuda headquarters was sealed off for 12 hours. Reuters reported a memo was sent to staff ordering that “no documents are to be destroyed and no files are to be removed”.